Improvement in steam-generators



UNITED STATES HORACE PEASE, OF DAYTON, OHIO.

IMPROVEMENT IN STEAM-GENERATORS.

Specification forming part of Letters Patent No. 140,070, dated June 17,1873 application led August 11, 1871. i

To all whom it may concern:

Be it knownthat 1, HORACE PEAsE of Dayton, in the county of Montgomeryand State of Ohio, have invented a new and useful Improvement inSteam-Generators; and I do hereby declare the following to be a full,clear, and exa-ct description of the same, reference being had to theaccompanying drawings, in which- Figure l is a side elevation of aboiler with my improvement attached. Fig. 2 is a perspective View of themethod of constructing my invention. Fig. 3 is a vertical centralsection of the same.

That others may fully understand my invention, I will more particularlydescribe it.

A is a steam-boiler, which may be constructed in any of the ordinary andwell-known ways. Upon the top of said boiler A, at a centralpoint., anopening is made and covered by a plate, B, of thinner metal than theshell of the boiler, and graduated in tensile strength in proportion tothe strength of the shell A- as for instance, if upon test it should befound that the shell A withstands a pressure of one hundred pounds tothe square inch, then the plate B might be graduated to withstand apressure of only fifty pounds per inch, and thus the maximum pressure towhich the boiler couldever be practically exposed could never exceedone-half that which the shell A would safely withstand.

In order to protect the boiler in this way, it is necessary that theplate B should be of comparatively large area, so that when ruptured themost rapid generation of steam would iind ample vent, which nopracticable safety-valve will be at all times able to do. I suppose torender safe a boiler forty-two inches in diameter and twenty feet inlength, a safety-plate of twenty inches in diameter `may be required.

The plate B should be made of copper in preference to other metal, notonly on account of its non-liability to corrode, but from the fact thatwhen ruptured, it would be less likely to shatter into fragments.

In some positions it will be of great importance that if a rupture ofthe safetyplate does occur it may be replaced with the least possibledelay-as for instance, on a locomotive-engine it would be important toput the engine in operation again with as little delay as possible.Ordinary bolts could not be removed and replaced until the boiler hadbecome cold, and the fire would therefore have to be drawn and the hotwater discharged; and as this would consume considerable time, the delaymight lead to serious consequences. I therefore employ the crank-screwsD and the wrench-ring E, as shown in Figs. 2 and 3. The binding-ring band safety-plate B can be released at all sides at once and wit-hout aclose approach by the workmen, and the ruptured plate removed. As soonas theissuing volume of steam has expended itself a whole plate, B,could be put in place and secured by a reverse movement of the ring E. Acrow-bar, or any other convenient lever, inserted through the loop e,and resting against the studf, will furnish ready means of' moving thefastenings of the plate B without the necessity of waitin g until theboiler becomes cooled.

Having described my invention, what I claim as new, is-

In combination with a safety vent-plate, B the crank-screws D and thewrench-ring E substantially for the purpose set forth.

HORACE FEASE.

Witnesses:

R. D. O. SMITH, E. R. MGKEAN.

